135x140 mm strapping bar, 160x45mm T-shaped joists - sized kiln-dried timber treated with preservatives and bio-based flame retardant (46x140 mm), 100x25 mm upper grating, 150 mm insulation, a bottom sheet of 12 mm cement bonded particle board, upper sheet of 16 mm cement bonded particle board, expanding foam, fasteners, joint sealer.